Surface measurement error for different methods. (a) Normalized cross-section
of the 3D result shown in Fig. 4(d);
(b) Normalized cross-section of the 3D result shown in Fig. 4(e); and (c) Normalized cross-section of the
3D result shown in Fig. 4(f);
(d)–(f) shows the difference between the 3D result with the fitted
smooth surface.